Touch sensors are input devices and are therefore typically paired with a complementary output device to provide a user with some form of feedback. In modern electronic devices this feedback is typically visual (i.e., a display). In smartphones, for instance, touch sensors are placed directly on top of displays to allow the direct manipulation of on-screen user interfaces. The display provides visual feedback and guides the user through the interaction.
When using a force-sensing touch solution, visual feedback can be implemented by actually printing visual indicators on top of the touch surface itself. For example, treadmills often have force-sensitive buttons behind a flexible membrane. This membrane is printed with a pattern that indicates button location and functionality. Some of these membranes also have raised edges to indicate boundaries between buttons. This adds tactile feedback for the user, and increases the interface's usability. Since the membrane is flexible, the user can transmit forces through the membrane and activate the force-sensitive buttons lying underneath. The membrane provides the user with adequate visual/tactile feedback, rendering a display unnecessary.
With this background as an application context, the present invention disclosure describes how physical augmentation of high-resolution force-sensitive touch sensors allows for the development of next-generation user interfaces. By replacing the set of discrete force-sensitive buttons with a high-resolution two-dimensional array of force sensors, the use of physical augmentation via overlays provides a much more powerful implementation and user experience. Instead of having a fixed set of buttons with a fixed membrane, it is possible to have one touch sensor that is compatible with an infinite number of membranes, each augmenting the sensor to add a different user experience. Touches may still be tracked across the entire sensor so much more data is available to application software directing the overall user experience.